The article is dedicated to the analysis of the methods of translation of onomastic realis in the Polish and Russian languages on the material of novels about Harry Potter by J.K. Rowling. In the onomastic space of novels 809 realities were singled out and were analyzed from the point of view of onomastics and translation studies and divided into groups of onyms: anthroponyms, zoonyms, toponyms, ergonyms, chrematonyms, praonyonyms, pragmatonyms, ideonyms. For each group the translation methods used by Polish and Russian translators were analyzed, the most frequent translation methods were highlighted. As a result of the study, a new classification of methods for translating onomastic realities was developed.